From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael Chan" Subject: Re: [PATCH net-2.6] tg3: Fix phylib locking strategy Date: Mon, 5 Oct 2009 14:29:57 -0700 Message-ID: <1254778197.8559.2.camel@HP1> References: <1254777182.18287@xw6200> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: "Felix Radensky" , "netdev@vger.kernel.org" , "andy@greyhouse.net" To: "Matt Carlson" Return-path: Received: from mms3.broadcom.com ([216.31.210.19]:1867 "EHLO MMS3.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753760AbZJEVjj (ORCPT ); Mon, 5 Oct 2009 17:39:39 -0400 In-Reply-To: <1254777182.18287@xw6200> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 2009-10-05 at 14:09 -0700, Matt Carlson wrote: > Felix, can you verify this solves your problem? > > --- > > Felix Radensky noted that chip resets were generating stack trace dumps. > This is because the driver is attempting to acquire the mdio bus mutex > while holding the tp->lock spinlock. The fix is to change the code such > that every phy access takes the tp->lock spinlock instead. > > Signed-off-by: Matt Carlson > --- > drivers/net/tg3.c | 37 ++++++++++++------------------------- > drivers/net/tg3.h | 1 - > 2 files changed, 12 insertions(+), 26 deletions(-) > > diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c > index f09bc5d..8afc60e 100644 > --- a/drivers/net/tg3.c > +++ b/drivers/net/tg3.c > @@ -902,11 +902,12 @@ static int tg3_mdio_read(struct mii_bus *bp, int mii_id, int reg) > struct tg3 *tp = bp->priv; > u32 val; > > - if (tp->tg3_flags3 & TG3_FLG3_MDIOBUS_PAUSED) > - return -EAGAIN; > + spin_lock(&tp->lock); > Matt, do we need spin_lock_bh() here? The tp->lock can be taken in NAPI poll BH context. > if (tg3_readphy(tp, reg, &val)) > - return -EIO; > + val = -EIO; > + > + spin_unlock(&tp->lock); > > return val; > } > @@ -914,14 +915,16 @@ static int tg3_mdio_read(struct mii_bus *bp, int mii_id, int reg) > static int tg3_mdio_write(struct mii_bus *bp, int mii_id, int reg, u16 val) > { > struct tg3 *tp = bp->priv; > + u32 ret = 0; > > - if (tp->tg3_flags3 & TG3_FLG3_MDIOBUS_PAUSED) > - return -EAGAIN; > + spin_lock(&tp->lock); > > if (tg3_writephy(tp, reg, val)) > - return -EIO; > + ret = -EIO; > > - return 0; > + spin_unlock(&tp->lock); > + > + return ret; > } > > static int tg3_mdio_reset(struct mii_bus *bp) > @@ -1011,12 +1014,6 @@ static void tg3_mdio_config_5785(struct tg3 *tp) > > static void tg3_mdio_start(struct tg3 *tp) > { > - if (tp->tg3_flags3 & TG3_FLG3_MDIOBUS_INITED) { > - mutex_lock(&tp->mdio_bus->mdio_lock); > - tp->tg3_flags3 &= ~TG3_FLG3_MDIOBUS_PAUSED; > - mutex_unlock(&tp->mdio_bus->mdio_lock); > - } > - > tp->mi_mode &= ~MAC_MI_MODE_AUTO_POLL; > tw32_f(MAC_MI_MODE, tp->mi_mode); > udelay(80); > @@ -1041,15 +1038,6 @@ static void tg3_mdio_start(struct tg3 *tp) > tg3_mdio_config_5785(tp); > } > > -static void tg3_mdio_stop(struct tg3 *tp) > -{ > - if (tp->tg3_flags3 & TG3_FLG3_MDIOBUS_INITED) { > - mutex_lock(&tp->mdio_bus->mdio_lock); > - tp->tg3_flags3 |= TG3_FLG3_MDIOBUS_PAUSED; > - mutex_unlock(&tp->mdio_bus->mdio_lock); > - } > -} > - > static int tg3_mdio_init(struct tg3 *tp) > { > int i; > @@ -1141,7 +1129,6 @@ static void tg3_mdio_fini(struct tg3 *tp) > tp->tg3_flags3 &= ~TG3_FLG3_MDIOBUS_INITED; > mdiobus_unregister(tp->mdio_bus); > mdiobus_free(tp->mdio_bus); > - tp->tg3_flags3 &= ~TG3_FLG3_MDIOBUS_PAUSED; > } > } > > @@ -6392,8 +6379,6 @@ static int tg3_chip_reset(struct tg3 *tp) > > tg3_nvram_lock(tp); > > - tg3_mdio_stop(tp); > - > tg3_ape_lock(tp, TG3_APE_LOCK_GRC); > > /* No matching tg3_nvram_unlock() after this because > @@ -8698,6 +8683,8 @@ static int tg3_close(struct net_device *dev) > > del_timer_sync(&tp->timer); > > + tg3_phy_stop(tp); > + > tg3_full_lock(tp, 1); > #if 0 > tg3_dump_state(tp); > diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h > index 524691c..bab7940 100644 > --- a/drivers/net/tg3.h > +++ b/drivers/net/tg3.h > @@ -2748,7 +2748,6 @@ struct tg3 { > #define TG3_FLG3_5701_DMA_BUG 0x00000008 > #define TG3_FLG3_USE_PHYLIB 0x00000010 > #define TG3_FLG3_MDIOBUS_INITED 0x00000020 > -#define TG3_FLG3_MDIOBUS_PAUSED 0x00000040 > #define TG3_FLG3_PHY_CONNECTED 0x00000080 > #define TG3_FLG3_RGMII_STD_IBND_DISABLE 0x00000100 > #define TG3_FLG3_RGMII_EXT_IBND_RX_EN 0x00000200